Design and Optimization of a Micro-Aerial Vehicle For Design/Build/Fly Michelle Acevedo Edson Novinyo Benjamin Andrews Luis Paredes Casey Brown Emily Perry Christopher Cahill Miles Schuler Ruxandra Duca Ashley Smith Emily Dunham Daniel Thiesse Mitchell Lentz AL2-1601 Design and Optimization of a Micro-Aerial Vehicle A Major Qualifying Project Report Submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE In partial fulfillment of the requirements for the Degree of Bachelor of Science in Aerospace Engineering by Michelle Acevedo _________________ Edson Novinyo _________________ Benjamin Andrews _________________ Luis Paredes _________________ Casey Brown _________________ Emily Perry _________________ Christopher Cahill _________________ Miles Schuler _________________ Ruxandra Duca _________________ Ashley Smith _________________ Emily Dunham _________________ Daniel Thiesse _________________ Mitchell Lentz _________________ April 26, 2016 Approved by: __________________________ Prof. Anthony B. Linn Aerospace Engineering Program Mechanical Engineering Department, WPI __________________________ Prof. Seong-kyun Im Aerospace Engineering Program Mechanical Engineering Department, WPI Abstract AIAA’s 2016 Design/Build/Fly Competition required the construction of two separate systems to complete distributive manufacturing missions. The team had to develop a production aircraft to carry a 1 kg payload and a manufacturing support aircraft which could carry the production aircraft internally. Aircraft designs were finalized using merit analyses and iterative design techniques to make quantitative decisions. The team selected a flying wing design for the production aircraft nested inside the wing of a conventional design manufacturing support aircraft as final configurations. The aircraft were manufactured and tested to ensure designs would complete mission requirements while maintaining the highest possible score by retaining minimal components and a low aircraft weight. “Certain materials are included under the fair use exemption of the U.S. Copyright Law and have been prepared according to the fair use guidelines and are restricted from further use." I Executive Summary The following report documents the efforts of Worcester Polytechnic Institute’s 2016 AIAA/Cessna/Raytheon Design/Build/Fly competition team during the background research, design, analysis, manufacturing, and testing of their aircraft entries. The 2016 Design/build/Fly competition challenges teams to construct two remote controlled electrically powered aircraft that will fulfill mission requirements and receive the highest total score, which is calculated based upon the grading of the written report, the aircraft’s flight scores, and the rated aircraft cost, a function which induces the total weight of both aircraft and the weight of the batteries used to power them. The emphasis of this year’s competition is to created aircraft optimized for distributed manufacturing, and requires the construction of two separate aircraft. The first, named the “Manufacturing Support (MS) aircraft”, must be able to fly three laps around the DBF competition course within 5 minutes unloaded in mission 1. In mission 2, the MS aircraft must internally carry each of the components of the second aircraft from a loading to an unloading area within 10 minutes. The second, “Production” aircraft, must be made such that it can be repeatedly assembled and disassembled without using glue, tape, or screws. In addition to needing to fit within the MS aircraft during mission 2, the production aircraft is required to carry the payload of a 32oz Gatorade bottle for its only flight (mission 3) which requires the aircraft to fly three laps around the DBF competition track within 5 minutes. Although decreasing the components of the production aircraft would increase the weight the MS aircraft had to carry during mission 2, a scoring analysis conducted by the team revealed that the winning aircraft tandem would consist of a production aircraft made up of no more than 2 components. Thus, the challenge for teams would be to create a production aircraft that was as light as possible to minimize the payload the MS aircraft must carry. An initial trade study helped our team identify a flying wing configuration to be optimal for both of our aircraft. The high L/W this configuration yields will help us excel in mission 2 and 3 while simultaneously keeping our rated aircraft cost (RAC) low. Additionally, the ability of flying wings to “nest” within one another, similar to a Russian Babushka doll, was identified as a means to minimize the total components of the production aircraft. Subsequent trade studies helped us select a single tractor motor and tricycle-style landing gear. An analysis program was II written in MATLAB was used to determine thrust and power requirements for each leg of the mission. Battery packs and motors were selected based upon this data, and were sized to exceed the predicted specifications by a safety factor of 20%. The program also calculated the distance each aircraft needed to take off, ensuring they would be airborne within 100ft, one of the mission requirements. Numerous iterations were run using different combinations of airfoils, batteries, and motors, and the most efficient configuration was selected. To increase the stability of the production aircraft, the Gatorade bottle was slung under the main frame. Its housing was 3D printed and reinforced with carbon fiber roving to increase its structural integrity without adding excess weight. The production aircraft is loaded into the manufacturing support aircraft upside-down through a hinged flap in the top of the MS aircraft’s airfoil. This flap is secured through the use of Velcro. A foam faring covers the fuselage and landing gear of the production aircraft. A tail was added In order to counteract the large moment created by the MS aircraft’s think airfoil. The tail also houses the MS aircraft’s control surfaces. Each subsystem of our aircraft were tested, and the results were compared to the predicted values, resulting in small changes to optimize results. Due to heavy winds at the competition, flight of the MS aircraft was only briefly achieved, whereas the production aircraft did not fly. III Acknowledgements We would like to thank the following individuals and groups for their help and support throughout the entirety of this project: Project Advisor Professor Anthony B. Linn Project Advisor Professor Seong-kyun Im Project Advisor Professor Nikhil Karanjgaokar WPI Faculty Professor Raghvendra V. Cowlagi WPI Students Jean Furter, Johnathan Griffin, Zachary Ligham, Austin McCalmont, John O’Neill, Kelley Slabinski, Club Millis Model Aircraft Club IV Table of Authorship Section Author(s) 1. Introduction 1.1 – 1.2 ED, ML 2. Conceptual Design 2.1, 2.4 CB 2.2, 2.4 AS 2.3, 2.5 ML 2.5 MA, MS 2.6 BA 2.7 CB 3. Aircraft Design 3.1 – 3.4 CC, EP, DT 3.5 – 3.6 DT 3.7 BA, ED, EN 3.8 AS, CB 4. Detailed Design Models 4.1 DT 4.2 CB, AS 4.3 – 4.8 RD, LP 4.7 BA 4.9 – 4.10 ML 5. Manufacturing 5.1 CB, LP 5.2 MA, CB 5.1 – 5.3 AS 6. Testing 6.1 CB 6.1 – 6.4 AS 6.2 DT 6.3 BA, ED, EN 6.5 MS 7. Final Results 7.1 – 7.2 AS 8. Conclusion 8.1 – 8.2 MA Appendices A – D CC, EP, DT E ML F RD, LP Final Edits References CC Editing and Formatting RD V Table of Contents Abstract....................................................................................................................................... I Executive Summary ................................................................................................................... II Acknowledgements ................................................................................................................... IV Table of Authorship .................................................................................................................... V Table of Figures ........................................................................................................................ IX List of Tables ............................................................................................................................. X 1. Introduction ......................................................................................................................... 1 1.1 Team Organization ...................................................................................................... 1 1.2 Project Gantt Chart ...................................................................................................... 3 2. Conceptual Design .............................................................................................................. 5 2.1 Design Constraints ....................................................................................................... 5 2.2 Mission Sequence........................................................................................................ 6 2.2.1 Mission 1: Manufacturing Support Aircraft Arrival .................................................. 6 2.2.2 Mission 2: Manufacturing Support Aircraft Delivery Flight ..................................... 6 2.2.3 Mission 3: Production Aircraft Flight ...................................................................... 7 2.2.4 Mission 4: Bonus Mission...................................................................................... 7 2.2.5 Mission Model ....................................................................................................... 8 2.3 Scoring Formula .......................................................................................................... 9 2.4 Sensitivity Analysis ...................................................................................................... 9 2.4.1 Aircraft Configuration Selection ............................................................................. 9 2.4.2 Payload Configuration ..........................................................................................11 2.4.3 Propeller Configuration ........................................................................................11 2.4.4 Landing Gear Configuration .................................................................................13 2.5 Material Analysis .........................................................................................................14 2.6 Battery Selection .........................................................................................................14 2.7 Conceptual Design Summary .....................................................................................15 3. Aircraft Design ...................................................................................................................16 3.1 Aerodynamic Analysis .................................................................................................16 3.2 Aerodynamic Analysis for Production Aircraft ..............................................................16 3.2.1 Initial Approach ....................................................................................................16 3.2.2 Second Approach: Weight Estimate .....................................................................18 VI 3.2.3 Second Approach: Airfoil Analysis .......................................................................18 3.2.4 Second Approach: Initial Sizing ...........................................................................20 3.2.5 Third Approach: Changes from the Previous Approach .......................................21 3.2.6 Third Approach: Methodology ..............................................................................22 3.2.7 Third Approach: Results ......................................................................................23 3.2.8 Control Surfaces Analysis ....................................................................................24 3.3 Aerodynamic Analysis for Manufacturing Support Aircraft ...........................................25 3.4 Stability Analyses ........................................................................................................27 3.5 Wing Tunnel Testing ...................................................................................................30 3.6 Final Design Parameters based on Aerodynamic Analyses ........................................32 3.7 Propulsion Analysis .....................................................................................................34 3.7.1 Motor and Propeller .............................................................................................34 3.7.2 Battery .................................................................................................................34 3.8 Structural Analysis ......................................................................................................35 4. Detailed Design Models .....................................................................................................36 4.1 Summary of Final Specifications .................................................................................36 4.2 Weight Balance ...........................................................................................................38 4.3 Fuselage - Production Aircraft .....................................................................................39 4.4 Fuselage – Manufacturing Support Aircraft .................................................................41 4.5 Payload Arrangement .................................................................................................43 4.6 Wings..........................................................................................................................44 4.7 Propulsion System Integration ....................................................................................45 4.8 Landing Gear ..............................................................................................................48 4.9 Expected Performance ...............................................................................................50 4.10 Rated Aircraft Cost ......................................................................................................50 5. Manufacturing ....................................................................................................................51 5.1 Materials Selected for Major Components ..................................................................51 5.2 Manufacturing Processes............................................................................................54 5.3 Manufacturing Milestones Chart ..................................................................................56 6. Testing ...............................................................................................................................57 6.1 Structural Testing ........................................................................................................57 6.2 Wind Tunnel Testing ...................................................................................................58 6.3 Battery and Propulsion Testing ...................................................................................59 6.4 Flight Checklist ...........................................................................................................60 6.5 Prototype ....................................................................................................................61 VII 7. Final Results ......................................................................................................................62 7.1 Final Aircraft Performance ..........................................................................................62 7.2 Competition results .....................................................................................................62 8. Conclusion .........................................................................................................................64 8.1 Outcome .....................................................................................................................64 8.2 Recommendations ......................................................................................................65 Appendix A – Aerodynamic Analyses Results ...........................................................................67 Appendix B – Initial Sizing Results ............................................................................................74 Appendix C – Detailed Airfoil Results for Production Aircraft .....................................................76 Appendix D – Detailed Results for Manufacturing Support Aircraft ............................................84 Appendix E – MATLAB Code for Power Requirement Calculation ............................................90 Appendix F – CAD Package .................................................................................................... 100 References ............................................................................................................................. 114 VIII